Risk Management Fundamentals: Position Sizing, Stops and Survival

Most trading education sells prediction. Risk management is the unglamorous discipline that decides whether your predictions ever get the chance to compound. A trader with a mediocre edge and excellent risk control will usually outlast a trader with a strong edge and no control at all, because the second trader eventually meets the position that ends the account.

The arithmetic of drawdown

Losses are asymmetric. A ten per cent loss requires an eleven per cent gain to recover. A fifty per cent loss requires a one hundred per cent gain. An eighty per cent loss requires four hundred per cent. This curve is the reason experienced traders speak about capital preservation with an intensity that seems excessive to newcomers.

• −10% drawdown → +11.1% required to break even
• −25% drawdown → +33.3% required
• −50% drawdown → +100% required
• −75% drawdown → +300% required

Position sizing: the one formula worth memorising

Position size should be derived from risk, not from ambition. The standard formula is straightforward: divide the amount of capital you are willing to lose on the trade by the distance between your entry and your stop, expressed in the instrument's value per point. The result is your position size. Notice that the formula never asks how confident you feel.

Suppose an account of 10,000 units of currency and a per-trade risk tolerance of one per cent, which is 100 units. If the stop is 50 points away and each point is worth 1 unit per contract, the position size is two contracts. Change the stop distance and the size changes automatically. This mechanical relationship is what prevents emotion from setting exposure.

Where to place a stop

A stop should be placed where the reasoning behind the trade is proven wrong, not at a round number that feels comfortable. If your thesis depends on a level holding, the stop belongs beyond that level with enough clearance for ordinary noise. If the resulting distance produces a position size too small to be interesting, the correct conclusion is that the trade is not worth taking — not that the stop should be moved closer.

• Structure-based stops: beyond a swing high or low that invalidates the setup.
• Volatility-based stops: a multiple of average true range, adapting to current conditions.
• Time-based exits: closing a position that has not performed within a defined window.

Risk of ruin and correlated exposure

Risking one per cent per trade sounds conservative until you hold six positions that are all effectively the same bet. Currency pairs sharing a base currency, index products tracking overlapping constituents, and digital assets during a market-wide move can behave as a single position. Aggregate risk, not per-trade risk, is what actually threatens an account.

Leverage is a risk multiplier, not a feature

Leverage does not create opportunity; it magnifies the consequences of decisions that were already made. High leverage shortens the distance between an ordinary adverse move and a margin close-out. Our platform research pays close attention to documented leverage tiers and margin rules for exactly this reason — see our notes on Global Reserve for how we assess published risk parameters.

Building a written risk policy

Professional desks operate under written risk limits because memory is unreliable under stress. Retail traders benefit from the same practice. A one-page policy that specifies maximum risk per trade, maximum portfolio heat, maximum daily loss and the conditions under which you stop trading for the day removes an enormous number of decisions from the moment when your judgement is worst.

• Maximum risk per position, stated as a percentage of equity.
• Maximum simultaneous correlated exposure.
• Daily and weekly loss limits that trigger a mandatory stop.
• A review cadence — weekly, monthly — for evaluating whether the rules are being followed.

The policy only works if it is written before the trading session, not during it. Rules invented mid-drawdown are not rules; they are rationalisations.